In semiconductor fabrication apparatuses and liquid crystal display substrate fabrication apparatus, a workpiece is required to be moved in a plane perpendicular to the gravity direction with precision and low vibration. A table carrying a workpiece or a working tool is moved by a driving source allowed to move individually on linear guides arranged orthogonally to each other. Precision and low vibration are required in this movement. Thus, the driving source does not employ a method that the output of a rotary motor is converted into linear motion by a ball screw, which is employed in common process machinery. Instead, a linear motor allowed to directly generate parallel displacement is employed as the driving source.
A general configuration of a linear motor includes: a field magneton part in which a plurality of permanent magnets are arranged such that the polarities vary alternately and which serves as a mover (or a stator); and an armature which is provided with a core constructed from a soft magnetic material including a plurality of magnetic pole teeth and with coils wound around the individual magnetic pole teeth and which serves as a stator (or a mover). The field magneton part and the armature are arranged opposite to each other with a given distance in between. When an alternating current whose polarity and magnitude are synchronous with the change cycle of a magnetic field relative to the moving distance of the field magneton part is applied to the coils, attractive and repulsive forces relative to the permanent magnets generate a thrust force in the moving direction. Thus, the field magneton part (or the armature) performs linear motion relative to the armature (or the field magneton part). Various types of linear motors having such a configuration have been proposed. For example, Japanese Patent Application Laid-Open No. 2008-125322 discloses a linear motor in which the field magneton part serves as a stator and the armature serves as a mover.